[extropy-chat] Re: Nano-assembler feasibility

[Chris Phoenix]

In this post, I will talk about technical issues.

Brett Paatsch wrote:
>>A simple mechanism can be constructed in many different
>>ways.  All you need is manipulators with a few degrees of 
>>freedom, and enough precision to do the job.  
> 
> I don't think I was assuming much about complexity at all. I said 
> anything from 300 to 300,000 parts. 300 parts would not be 
> particularly complex.
> My point was there is no specification for a system to produce an 
> assembler of any finite number of parts. 

Talk of 300,000 parts makes it sound like we have no clue how complex it 
must be.  That's flatly wrong.  Have you read Merkle's papers?

> The assembler (however complex) has to be *physical* to make
> physical objects. There are no computers completely without 
> hardware. If the computer is not part of the assembler then 
> its not a self-replicating system, if it is, the parts for the computing
> subsystem have to be included in the parts for building the first
> assembler.  

Irrelevance, followed by topic change, followed by false dichotomy. 
That the manipulator has to be physical is a no-brainer, and I'm 
surprised you brought it up.  The computer may or may not be nanoscale, 
depending entirely on what's easiest.  The first assembler can be 
controlled by an external computer.  As we scale up to thousands or 
trillions of assemblers, we can include maybe one nanoscale computer for 
every thousand assemblers, adding moderately to the design work and 
fractionally to the mass.  Have you read my nanofactory paper?

> How do you know that "a computer-controlled assembler can
> be physically quite simple" without have a specification for it that
> includes a set of physical components? Do you have such a 
> specification showing a finite set of component parts? 

We have a specification that includes most functional components, and 
supplemental information about range of motion, required stiffness, 
speed, etc.  We know the functions it must perform.  Your question about 
a "finite set of component parts" doesn't make sense, unless you intend 
to imply that it might require an infinite set.  At this point, twelve 
years after Nanosystems and half a decade after Merkle's papers, such an 
implication would be silly.

> And if it is merely a statement of hope and belief why should 
> public resources be directed towards it and away from other
> projects that can show a return on investment?

Are we talking engineering and science, or politics?  I thought we were 
talking engineering, but "hope and belief" and "return on investment" 
sound political--and shallow.  If we're talking politics, then we should 
mention the geopolitical implications of some ambitious nation making a 
breakthrough while the current superpower is saying, "Let's not try 
anything till we see it done."  But if I were to start talking about 
that, you'd say that I was being alarmist by talking about possibilities 
that haven't been scientifically proved.

We could go for weeks with you always taking my statements out of 
context: criticizing my technical statements from a political point of 
view, and vice versa.  I have played that game before, and I don't have 
time for it now.

I strongly suggest that we begin each post, as I did, with the 
statement, "In this post I will talk about technical issues" or "In this 
post I will talk about political issues."  Funding, political 
implications, economic implications, return on investment, whether to 
investigate it... all are political.  Number of parts in an assembler, 
energy per kilogram fabricated, whether the computer can or must be 
miniaturized, researchers / years required to build the first 
assembler... all are technical.

If you answer a technical point with politics, I will point out your 
error rather than answering you.

Chris

-- 
Chris Phoenix                                  cphoenix at CRNano.org
Director of Research
Center for Responsible Nanotechnology          http://CRNano.org